Pernicious Anemia

B-12 Deficiency Anemia

Basic Information

What is Pernicious Anemia?

Anemia caused by inadequate absorption of vitamin
B-12 (cobalamin). Vitamin B-12 is found only in food of
animal origin, such as meat, fish and dairy products.
This anemia more often affects adults between ages 50
and 60. The symptoms of pernicious anemia develop
slowly and subtly and may not be recognized right
away.

Causes

Absence of intrinsic factor, a chemical secreted by the
stomach's membrane lining that makes absorption of
vitamin B-12 possible. The reason for the absence of
intrinsic factor is unknown, but it may be a genetic deficiency
or autoimmune disorder.

Decreased production of hydrochloric acid, especially
following stomach surgery or in combination with the
absence of intrinsic factor. Hydrochloric acid is also
necessary for absorption of vitamin B-12.

Genetic factors. The disorder is most common in people
of Northern European ancestry. It is rare in Blacks
and Asians.

Preventive measures

If you have had stomach surgery or gastritis, have regular
vitamin B-12 injections. See Medications.

Expected outcomes

This condition is currently considered incurable.
However, regular vitamin B-12 replacement will control
symptoms indefinitely and reverse complications. Some
symptoms should start to disappear within a few days
after treatment begins, while others may take several
months.

Medications

Vitamin B-12 injections are usually prescribed. The
amount depends on the extent of your illness. The
usual dosage is 1 injection a day for 7 days, then 1 injection
a week for 1 month, then once a month for the rest
of your life.

Learn to give yourself vitamin B-12 injections, because
oral supplements are inadequate. Lifetime treatment is
essential. Even with treatment, your ability to absorb vitamin
B-12 will not be normal.

Activity

Physical activity may need to be restricted until symptoms
of weakness and balance problems disappear.

Diet

No special diet. Raw meat and raw liver are no longer
prescribed.

Iron supplements may be necessary.

Notify your physician if

You or a family member has symptoms of pernicious
anemia.

Symptoms don't start to improve in 2 weeks after
treatment is started.